5. Male and female patients who are fertile agree to use an effective barrier method of birth control (e.g., latex condom, diaphragm, cervical cap, etc.) to avoid pregnancy. Female patients need a negative serum or urine pregnancy test within 14 days of study enrollment (applies only if patient is of childbearing potential. Non-childbearing is defined as >/= 1 year postmenopausal or surgically sterilized).